A novel chromaticity space is disclosed that may be used as a framework to implement an auto-white balance solution or other color image processing solutions that take advantage of the particular properties of the novel chromaticity space. The chromaticity space may be defined by using a series of mathematical transformations having parameters that are optimized to adapt to specific sensors' spectral sensitivities. The unique properties of the novel chromaticity space provide a conscious white point constraining strategy with clear physical meaning. In this chromaticity space, the ranges of possible white points under different kinds of lighting conditions can be defined by polygons. Because of the physical meaning the chromaticity space, the projection that is needed to bring an initially “out-of-bounds” white point back into the polygon also carries physical meaning, making the definition of projection behavior and its consequences conceptually clean and predictable.